The objective of this study is to investigate () the development of toddlers' attention span in children of depressed and well mothers; (b)\maternal influences on the development of attention and (c) the effects of depression on mothers' ability to regulate their young children's attention span. There is very little information about the development of attention in the transition years between infancy and early childhood. In addition, the role of mother as a regulator of a child's attention is not well understood and calls for detailed investigation. Attention, like many other skills may need to be at least partially trained. Mothers, through their interaction with their children, are hypothesized to provide such training. They are hypothesized to recruit their children's attention and to maintain it through their involvment, feedback regarding the children's activity and through reinforcement. Since depression entails a diminished ability to concentrate, loss of interest in usual activities and irritability, depressed mothers are hypothesized to be less likely than well mothers to train their childen's attention. Consequently, children of depressed mothers are hypothesized to have deficits in attention. 29\depressed women (unipolar depression) and 29 well women were observed with their children. The childen were between 16 and 44 months at the initial observation and some were already observed 3 years later. Preliminary analyses indicate that toddlers of depressed women have a shorter attention span.